James Purnell takes up Blairite thinktank role

The former cabinet minister James Purnell, whose resignation from the government this month nearly toppled the prime minister, is to take on a new job heading up a project at the thinktank Demos developing ideas for the future of the left.

The move gives the former work and pensions secretary a base and funds on which to build ideas he felt unable to explore within government.

Purnell was the most senior cabinet minister to resign at the height of challenges to Brown's authority and of the eleven ministerial departures that knocked the government, Purnell issued the most explicit criticism of Brown calling on the prime minister to step down.

At Demos Purnell joins figures critical of the prime minister's style and agenda. Blair's former speech writer Phil Collins is a Demos trustee. Alan Milburn, the former health secretary and critic of the prime minister, who announced on Saturday he would retire from his Darlington seat at the next general election, is also a board member. Demos has also hired Purnell's former special adviser Graeme Cook.

The thinktank was established in the mid-90s by former Blair adviser Geoff Mulgan and though it has frequently published pamphlets by non-Labour figures, government sources were perplexed when Demos used the occasion of its 16th birthday in May to appoint to its board politicians from the Conservative and Lib Dem parties including the shadow chancellor, George Osborne, and Treasury spokesman for the Lib Dems, Vince Cable.

Relations between Demos and the government had already soured over the last year with the thinktank's decision to hire the conservative academic Phillip Blond to develop ideas of "progressive Conservatism". In the forthcoming days, Blond will announce he is leaving Demos to set up his own thinktank.